Massage machines of the chair type are available which have a chair for a person to sit in to have his or her neck, shoulders, back or waist massaged.
The chair-type massage machine comprises a massage unit provided inside the backrest of the chair and movable upward and downward. The massage unit has a pair of opposite therapeutic fingers each comprising a massage arm bent at an obtuse angle and carrying a pair of kneading balls respectively at opposite ends thereof, and a pivotal arm for three-dimensionally moving the massage arm leftward, rightward, upward, downward, forward and rearward.
The massage arm is supported by the pivotal arm and biased by a spring so as not to freely rotate relative to the pivotal arm and to position the upper kneading ball as projected forward slightly beyond the lower kneading ball [see, for example, the publication of JP-A No. 2002-143253 (page 4, FIGS. 1 to 3)].
The chair-type massage machine has its backrest covered with a fabric cover or the like. It is likely that the fabric cover will be tensioned by the user leaning against the backrest. If the fabric cover is tensely stretched when a massage is to be given to the person, the massage arm is forced by the cover to stretch the spring when to be tilted, with the result that the massage arm is unable to incline, failing to deliver a sufficient therapeutic force to the person to be massaged.
Difficulties are encountered especially in giving a kneading or tapping massage to the shoulder unless the upper kneading ball is pushed out forward when massaging the upper portion of the shoulder of the person to be treated.
An object of the present invention is to provide a massage machine of the chair type wherein massage arms provided with kneading balls can be held inclined forward so as to give a suitable massage.